The present invention relates to an image forming apparatus, and can be applied, for example, to an image forming apparatus that is provided with operating means for handwriting, which the user inputs by writing on a touch panel or the like, and that attaches signature information to a plurality of documents, and outputs it.
Conventionally, a technology for attaching a signature which a user inputs by handwriting to a plurality of documents and outputting it is disclosed, for example, in Japanese Unexamined Patent Application Publication No. 3-136165, and so on.
In Japanese Unexamined Patent Application Publication No. 3-136165, it is disclosed that additional information that has been created according to a predetermined rule which only the signer himself/herself and concerned persons know is added to a signature which the user has input, at a predetermined position, and is attached to documents as a piece of signature information to be output.
In this way, although a conventional document creation method, in which a signature input by the user is attached to a plurality of documents, can be applied, it is difficult to determine whether each document having the signature attached thereto is an authentic document or a copy.
In other words, a plurality of copies that are the same as an authentic document in appearance can be made. Thus, the copies may undermine the credibility of the authentic document.
Further, the conventional document creation method stores the signature itself, which has been input once, in storage means of an apparatus, and the signature can be read out to be utilized for other documents upon request from the user, which causes a security problem in that the signature can be read out without the permission of the signer himself/herself and used.